1972 Fury Filler Tube Gasket… which direction please?

My old one was cracked and leaking... put this new one in and been fine but I havent put a lot of gas in it til yesterday and I got seepage. Looks like the ridge on the tube sits inside a space in the seal and I am not sure if I had that right. But I am not sure on the rubber seal if the rounded part faces rearward or goes in side the tank...

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Author: MBar